[5] Though the common rhododendron was present in Great Britain prior to the most recent ice age, it did not recolonise afterwards and the modern ecology of the island developed without it.

Its presence today in Great Britain is due to humans introducing it, and it easily naturalises and becomes a pest in some situations, often covering whole hillsides (especially in Snowdonia and western Scotland).

In the British Isles, it colonises moorlands, uplands, shady woodlands (alongside escaped laurels and the native holly) and in areas of acid soils.

[6] It was noted by the botanist Joseph Pitton de Tournefort during his travels in the Near East in 1700–02, and so received its name from Linnaeus to identify the ancient kingdom on the south shores of the Black Sea, Pontus, in which it grew.

The plants were first grown in Britain in the 1760s, supplied by Conrad Loddiges, and became widely distributed through the commercial nursery trade in the late 18th and early 19th centuries.

[12] A study[13] in the journal Functional Ecology also showed that invasive rhododendron nectar was toxic to European honeybees (Apis mellifera), killing individuals within hours of consumption.

The toxicity is caused by grayanotoxin 1 which is one of several highly hydroxylated diterpenoid defence chemicals produced in the leaves of Rhododendron to protect against herbivores – e.g. the Thrips Heliothrips haemorrhoidalis.

Recent efforts to manage the spread of Rhododendron ponticum in the United Kingdom has led to some controversy, particularly within the grounds of Taymouth Castle in highland Perthshire.